Gumball Dosn't Know
by HiyaKitty
Summary: Fionna and Gumball have a great relationship and a practically non-existent love life. But when Marshall Lee comes along and offers her a date, Fionna can't help but say yes. She knows cheating is wrong. She knows it's wrong to lie. She knows it's wrong to sneak out at night to meet him. But everything about Marshall Lee is just wrong enough to make it feel right.
1. Chapter 1

**Gumball Doesn't Know**

**So this story was inspired by gothgirl916's video "Fionna x Marshall Lee – Prince Gumball doesn't know". I recommend you all go to her channel and watch it and all her other great videos. I have summer holidays now and should be able to update regularly. If I don't, forgive me.**

**And this is a song-fic of the song "Scotty Doesn't Know" using the pairing Fionna and Marshall Lee from the show Adventure Time.**

**So this is a Fiolee fanfiction. I'm not a full-fledged shipper of Fiolee. I have to see the chemistry between her and Flame Prince before I make my full decision on who I ship Fionna with. But Fiolee has its vampire fangs bitten deep in my heart. I really like it. So Fionna x Flame Prince has its work cut out for it when it actually rolls around on the show.**

**So, ANYWAY, along with the story. I hope you all enjoy!**

Chapter 1; Dark Figure On the Balcony

Fionna sighed and looked at her reflection in the mirror. She was wearing a satin blue dress that ended just above her knees, along with her usual shoes and high socks. The dress was one Cake made her. It had short sleeves and a lot of netting under the skirt, making it poufy and stand out a lot. It also had a large bow at the back which Cake was currently tying for her.

Fionna sighed once more.

"Fionna, you're going to a _party_" Cake said "Why are you sighing so much?"

"It's just- It's just that _Gumball _is throwing the party" Fionna explained.

"So? I though you liked him?" Cake said, confused

"I do! It's just-I don't even know how to explain it. I like him, yeah. But….." Fionna trailed off

"But…..?" Cake asked, raising an eyebrow.

"That's the thing. I like him, but there's a "but". If you really like someone shouldn't there no buts? Shouldn't it just be "I like him" and nothing else?"

"Fionna, you have to let things take their natural toll." Cake said, very matter-of-factly. "Maybe you just need to give it a little time"

"I dunno, Cake, maybe" Fionna said, vaguely

"OK, you're ready now" Cake said, turning the topic away from boys and onto dresses.

Fionna turned and faced her.

"You look lovely, suga" Cake said "Thanks, Cake, so do you"

"Thanks, Fi. Now let's get going"

Fionna picked up her purse.

"OK, let's go" she said, showing a weak smile as she through of having to see Gumball and be reminded yet again that there was a "but"

"Fionna, you look ravishing, this evening" Prince Gumball said, placing a kiss on her hand.

"Thank you, Gumball" Fionna said. She couldn't help but smile. He was so sweet. But his kiss didn't make her heart beat any faster or send chills down her spine or anything. It was just a kiss from a sweet guy. It made her smile all the same.

Fionna went inside the ballroom, while PG went on welcoming his guests. Cake quickly scampered off to go find Lord Monochromocorn.

"You don't mind being alone, do you, suga? Cause I can stay if you want." Cake she had asked.

"No, you go ahead and look for your boyfriend." Fionna had smile "I'll have Prince Gumball soon as he finishes welcoming his quests"

"OK and Fionna"

"Yeah?"

"Let things take their natural toll, alright?"

"Alright"

Fionna waited and waited. Then she waited some more. In fact she waited far longer than she really wanted to. But eventually Gumball was finished welcoming guests.

Gumball found her as soon as he was done. He kept her by his side for the next hour or so. Introducing her to every guest they mingled with and putting his arm around her as he did so. As soon as Fionna had been introduced, Gumball and his guest would fall into deep conversation, and Fionna would contribute to it best she could. Every so often someone would ask her about her adventuring, which she was more than happy to talk about.

_This isn't so bad_ Fionna thought to herself. True, she would prepare to have Gumball all to herself. But it wasn't so bad, all the same.

Gumball also seemed to be thinking this.

As soon as they a moment to themselves, she felt Gumball take her hand.

"Fionna, come with me" he whispered, leaning in to her.

"OK" she whispered softly back

Holding her by the land, he lead her through the swarms of guest to the end of the room, where two fancy glass doors stood. He opened the door for her.

The door lead out to a balcony. She stood out onto, Gumball following her. The air was cold and she started to wish she had brought a jacket or something with her. It was a dark night in the Candy Kingdom and above her head a billion little stars shone like fairy lights in the inky blue night.

Gumball put his arm around her.

"Fionna, I think we need to talk"

"OK" Fionna said, uncertain. Had she done something wrong or something?

"Fionna, how long have you and I been together now?"

"Six Months" she answered. Was he breaking up with her? She knew the idea should upset her, but it didn't. It felt like someone had given her heart a small punch, yeah. But it was far from broken.

"Fionna, I" He started, and then stopped. "I-I feel the need to tell you that-that…"

"Yeah?" Fionna asked, gently. Preparing or the worst.

"I-I really-" He looked directly in her eyes. "Really like what we have" He pulled her close, into a hug.

Fionna stood there, started led for a moment before wrapping her arms around him.

"I really like what we have too, PG" she said

Then Fionna saw something out of the corner of her eye. A dark haired figure, sitting on the corner of balcony, just watching them. Fionna craned her neck to get a better view of the person. Gumball noticed

"What?" He asked, looking over his shoulder.

As he turned his head, the figure vanished.

"Oh, I thought, I saw…" Fionna trailed off. "Y'know what it was probably nothing"

"Oh, alright" Gumball said, shrugging.

He took her hand. "Come on, let's get back inside"

"Sure" Fionna said, only Half-listening.

She wasn't able to see that figure perfectly in this light but she thought it had been Marshall Lee.

As she and Gumball re-entered the ballroom she couldn't help notice that the idea of Marshall being here made her heart beat faster in a way Gumball hadn't made her heart do for a long time.

**OK, Folks, tell me what you guys think. This chapter isn't my absolute best. I promise the next chapter will be less rushed and more descriptive. And it will have Fiolee fluff. So much fluffy fluff.**

**HiyaKitty out**

**X (Blows Kiss)**


	2. Chapter 2

**OK, sorry for the delay, people. I'll try harder next to update quicker. But anyway here's the second chapter.**

**Chapter 2:**

_Fionna's POV_

I stood in the girl's bathroom looking at my reflection in the mirror. I had managed to slither away from PG for a while, just to get away from it all.

Six months, that's how long we had been together. Six months and we hadn't even kissed each other. Not properly, not on the lips. He had kissed me on the cheek and on the hand a few times. Sometimes I got the impression that how was avoiding it. Was there something wrong with me? Was there something about me that made me pretty much unkissable?

Noticing that one of my socks was slipping down I bent over to pull it up, my reflection disappearing from the mirror.

When I straighten up and my reflection reappeared again and jumped when I saw a person that hadn't been a few minutes ago standing behind me.

I whirled around and found myself face to face with Marshall Lee.

"Marshall, what are you doing in here?" I asked "This is the _girl's_ bathroom"

"Well, I waited for you outside for ages, but you took too long. So I came in"

"Yeah, that sounds like you" I say rolling my eyes.

"Anyway" he said "You wanna go to a _real _party?"

"I can't, Marshall" I said "Gumball already invited me to this party"

"So? He doesn't own you" Marshall said, a note of irritation in his voice, due more to the mention of Gumball's name, then my refusal to go.

Suddenly he leans into me, face inches from mine. "Let's ditch him" he whispers. He places a hand on my shoulder and with his other hand he traces a finger along my jawline, sending shivers rushing down my spine.

"You know you what to" he practically purrs

"I – I shouldn't" I say slowly

"Aw, C'mon" he says his voice gentle and playful

"Well – Well….OK, yeah, yeah I guess I could…." Then even thought I didn't want it to, common sense seeped into my head which beforehand had been fogged with Marshall Lee's dreaminess.

"No, no, Marshall. Me and PG are together. It would be wrong for me to sneak off with you, I can't"

"Don't think of it as sneaking off, think of it as a momentaril disappearance"

"Marshall, the answer is no"

Marshall's hands dropped from my shoulder and my neck. He turned and started to leave, hands in his pockets.

"OK, whatever" he said shrugging "I guess I'll find another girl to go on an adventure with me"

My ears pricked up at the word "adventure".

"There's an Adventure?" I said, eagerly

Marshall stopped and turned to me "Thought you weren't interested?" he said, teasingly. He knew he had me. He knew I craved adventure the same way a diabetic person craved insulin. He knew I wouldn't be able to resist. He had me right where he wanted me…and he was loving every second of it.

"Ok, I'll go with you" I said, after a few seconds of consideration. A pleased smile slithered across his lips.

"Excellent" he says.

He takes my hand and leads out of the bathroom and down the hall. I'm nervous and for two reasons. One is because Gumball could see us at any moment and two because Marshall is holding my hand. For some reason that makes my heart do a somersault in my chest.

We get to the end of the hallway and stop at one of the windows. Marshall unlatches it and steps out onto the ledge. He holds out his hand for mine. I slide it into his. Then, before I know it he drapes my arm around his shoulder and wraps his own arm around my waist.

"Hold on tight, Bunny" he says.

And then we take off, my feet leaving the ground. And like that where flying through the night sky.

_A Little later_

Me and Marshall don't speak during the whole flight, we share only a comfortable silence.

I feel slightly awkward knowing that this is the closest to Marshall I possibly ever have been. But he holds me securely and I safe. I know I can trust him.

The view is brilliant. The view I have of Marshall isn't half bad either. The moon seems to illuminate his skin and put a sparkle into his eyes. He notices my staring.

"Taking in my good looks, Fionna?" he asks, smiling.

"What?! No!" I say, the colour crimson invading my cheeks. I feel my face grow warm as Marshall laughs at my reaction. I feel him place a cold hand on my cheeks, cooling them.

"Hey, relax" he says softly and I do. "We're almost there now"

"Where are you taking me, anyway?" I ask

"You'll see" he says

And then we fall back into that comfortable silence.

**OK, sorry for how short this chapter is, but I hope you like it anyway.**

**Love you all x (Blows kiss)**


	3. Chapter 3

**Chapter 3:**

**In the dark**

Marshall and I land in what looks like a wasteland. There seems to be no life anywhere, let alone adventure. Heck, there isn't even tumbleweed blowing by.

I raise an eyebrow at Marshall. Is this a trick? Dib he whisk me away from the party purely just to get on PG's nerves?

"Well, this looks adventurous" I say sarcastically

"It is" Marshall says, shrugging. "_If _you know where to look" With that he drags his foot along the dirt, revealing a wooden surface.

"Is-Is that a trap door?" I ask as he scrapes more dirt away, showing more wood.

"Yep" he says "Can you guess what's down there?"

"Is it?" I asked. Heart bubbling with excitement "a dungeon?"

"A _mystery _dungeon" He said

Both of us kneel down and scrape away the remaining dirt and heave up the trap door. It opens to reveal pitch blackness, but the beginning of a ladder is visible. Marshall smiled at me.

"Ladies, first" he said, I rolled my eyes but he didn't need to tell me twice. I slowly and steadily began down the rusty ladder.

A little while down I saw Marshall follow me in pursuit, closing the trap door behind him, plunging up into darkness.

OK, I had gone on Dungeon Crawls in the dark before, but for some reason the idea of Marshall and me being alone in dark together made me… I dunno… scared and nervous at the same time.

I make it to the ground of the dungeon.

"Um, Marshall, can I ask you something?"

"Sure thing"

"How do you propose we see in the dark while where down here?"

" Because I know you so well, I assume you have your retractile sword with you in that purse and if I remember correctly that thing glows so you should be able to use it as some kind form of flash light."

OK that was true.

"And I'm part vampire, meaning I'm part bat, which means I have night vision. So I'll be doing some of the seeing for you. So I'll have to act as your eyes"

Ok, once again that makes my heart do a weird backflip in my chest. Geez, all these weird things Marshall makes my heart do, it can't be good for it.

Then he does something that catches me completely off guard and makes me jump with surprise. He grads my hand.

"But to be on the safe side we should probably hold hands just so we don't get separated, OK?"

"O-OK" I say, shaking inside. With my free hand I rummage in my purse for my sword. I feel my feel my fingers enclose around the small neon pink blade and pull from my bag as I make it larger and ready for battle. Marshall's hand is cold, but a pleasant kind of cold. Me and him walk forward, me with difficulty as my knees have turned to mush. And Marshall floats really instead of walks.

We don't say anything but we walk in silence. Part of me wonders should I strike up a conversation but my mind draws blank on anything to say. I mean what was I even meant to say? _Hey Marshall, I'm having a great time sneaking away from the party that the guy I'm apparently meant to be in a relationship with is throwing to go on a great dungeon crawl with you because I think I may have deeper and stronger feelings for you. Just thought I should bring that up. _Yeah, right.

To be honest, I think I did have stronger feelings for Marshall. I mean, when I'm with PG feel safe and like I can just relax, same why I would around a friend.

But with Marshall I feel like on edge, I find myself always thinking if he's thinking about me, and if so in what way? Does he think of me as a little sister? As a friend? As Fionna the chick whose head he loves to mess with?

And then there was the thing I really hoped he didn't think of me as. I really hoped he didn't see me as some uncool, innocent, silly little girl. As a goody two shoes who was afraid to break the rules. Or as a _baby_. When I was with him I felt like I was dabbling in something dangerous, something dark. I feel more devious, like someone who shouldn't be messed with. Problem is, I'm really starting to like that feeling. And I only feel this way around him. And I really don't know if I should feel that way.

It's like I can see our potential future unfolding in front of me. I mean, me and him can never be right? And it's not just to do with the fact he's a vampire and I'm human. Nobody would be happy to see good girl Fionna date bad boy Marshall. Me, who lived in a world of being a hero and doing right. Him, who lived a world that was reckless and mysterious and burned bright. With pretty much everyone against us, would we even last long in a relationship?

I've never felt like this before. Maybe that's why I feel on edge. Maybe I'm scared of losing myself.

But despite all this, he's leading me through a dungeon in the dark, holding my hand and you know what? I have full trust in him. Is that crazy?

But I'm over-thinking all this aren't I? I mean for all I know Marshall may not even see me in that light. He probably feels the same way about me most boys do. He probably sees me as a guy friend.

Holding hands is probably as close as will get tonight.

Oh, how very wrong I was.

**Ok, once again, really sorry for the shortness of this chapter and how rambly it was. Either way I'm hoping you guys still liked it.**

**Remember now Reviews are love**

**HiyaKitty out**

**(blows kiss)x**


	4. Chapter 4

**Chapter 4**

**Ok guys here's a nice long chapter for you all with a lot of fluffiness, enjoy! **

_Marshall POV_

Logic has deserted me_._ She's four years younger than me. By logic's sake, I shouldn't find her attractive, but I do, very much so. Just something about her blonde hair, ivory skin and cute little round face makes her so damn irresistible.

She's shorter than me, but in a weird sort of way I like that. It makes me feel protective of her and somehow it adds to her cuteness.

Does she act like she's four years younger than me? Not necessarily. I can't tell if she's mature for her age, or if she's just heroic for her age. Is there's difference?

Deep down I wonder if she has a crush on me. I was convinced she did a while back, like when I pretended to be dead and told her to just admit it. (And, OK, I understand it now that was going too far). But it's different now. Back than it was just sort of like "Oh, I bet Fionna has some little crush on me, aw, that's so cute" but now it's more "I really hope Fionna has a crush on me" This time I actually really _want _her to. Like, _really, really,_ want her too.

And I hate the way that Gum wad treats her. He doesn't really love her, he's just stringing her along and she's too polite to break up with him.

Like earlier this evening for example. They were alone together on the balcony, underneath a starry night sky, in private. I'm sorry but that scenario pretty much screams "smooch-worthy moment" and he _hugged _her. If it had been me, I would have been kissed her. Why? Because a girl like Fionna deserves a kiss, not a hug.

_Line Break_

Marshall is the first to talk.

"How's your relationship with Gumball going?"

"Oh, you know, it could be better, but…." The sentence goes unfinished.

"But…?" Marshall persists

"It's just…not what I thought it would be"

"Well, what did you think it would be?"

"I don't know, I just thought… I just….I just don't feel all the rushes and chills down the spine I thought I'd feel. The stuff I thought I was meant to feel."

"You deserve better"

"I thought they didn't come better than him" she sighs "I mean I crush on him for ages, we finally get together and then it's like….I just want to back to being friends" She looks directly into my eyes. "Marshall, can…can we just change the subject. I – I just don't want to talk about this anymore." She shrugs and looks away "Feelings can just get complicated sometimes, y'know?"

"Sure thing" I say "What do you want to talk about?"

"What I really want to know is how did you find this dungeon?"

"Oh, this is an old Vampire Dungeon. This was probably some big vampire's hideout ages ago. But don't worry its deserted now."

Just as Marshall says that, we hear noise. I raise my sword, ready for battle and listen closely for any further sounds, the way Cake does when I open a tin of tuna.

I hear something scuttle against the ground behind me. I turn around fast and me and Marshall's eyes come to rest on a living skeleton. I'm not surprised. Even in Vampire Dungeon's living skeletons are so common they practically boarder on Stereotypes.

I hold up my sword.

"You're the Adventurer, Fionna. So what do we do?"

"Simple, we over-power them with confidence"

"Arrrg! You're going to surrender!" I shout loudly.

"Arrgh!" he shouts back

"Arrgh!" I shout back once again. It goes on like this for a good twenty seconds before he finally gives up. After I force him to do the splits I interrogate him for information on the Dungeon.

"OK, now hand over any important loot you have on you or taste the blade of my sword!"

"OK, OK, geez" The Skeleton groans, his hand reaching into his ribcage returning with a key and a map.

"Here" he says shoving it at me. "This is all I got"

"Good" I say taking it off him.

I turn to Marshall who's looking at me, mouth open slightly

"Wow, Fionna, That was pretty hardcore" He says, impressed.

"Oh, it's nothing really"I say although I'm blushing like crazy.

Is it weird that fighting a skeleton bad guy doesn't scare me at all but the Marshall giving me a compliment is what makes me melt?

Thank Glob he doesn't seem to see the colour red that's shining on my cheeks. And if he doses he's doing a really good job of pretending he doesn't.

"So what's that map say?" He asks

"Well" I say trying to get my cheeks to cool down. "It seems to direct us to a secret entrance to another part of the cave."

"Great. I'll direct us" he says taking the map out of my hands.

"Wait. Why will you direct us?"

"Because, I'm the only dude here." He explains "And everyone knows girls are terrible with directions"

Ok now that I'm going to have to object to that.

"What do you mean?" I say, eyes narrowing.

"I'm just saying men are naturally better at something's then woman. And reading directions are one of them" he shrugs "Simple as"

"Well too bad I'm the adventurer here and I'm in charge!" I say proudly. I snatch the map out of this hands and striding forward.

"Hey, wait" I hear him call after me "Fi, what about our holding each other hand's rule"

"I breaking that rule" I say simply, shrugging.

"Well, well, Fionna. Breaking the rules, that's unlike you, the good little girl" I hear him say and I can practically hear him smiling as he says that. I'm not impressed, I keep walking forward.

"Oh what are you gonna do, spank me?" I say, rolling my eyes. I almost stop in my tracks at what he says next.

"Don't tempt me" he says, his voice rich and seductive. I am suddenly very aware that I'm in front of Marshall and after what he just said he could be very easily admiring my butt. I whirl around and I see Marshall's eyes dart up, pretty much proving my suspicion.

Oh great. My cheeks are glowing red again just as I got them to calm down.

Marshall plucks the map from my hand. Smiling, because he's got his way.

I follow him he directs us forward. I feel his hand slip into mine. I like how familiar that feels now.

Eventually we find ourselves at a huge grand door, decorated from top to bottom in bones.

I hold up the key and slip it into the lock and turn it. Both me and Marshall heave the door open. It makes a loud groaning sound as it does.

When we finally manage to get onto the other side of the door. The room it leads into is coated in cobwebs and drowning in dust. I take a few steps, cautiously. Slowly, hand and hand with Marshall, we walk across the hall, your feet being possibly the first to touch the ground of this place in years.

Slowly I hear a scuttling sound. Then to my excitement I see something moving in the darkness. What it is I don't know it is but I could be some bad guy I could fight.

One by one more living skeletons appear, dozens of them.

"Marshall, you ready for a fight?" I ask

"Fionna, I was _born_ ready" Marshall says, just as eager for some action as I am.

The skeletons just keep coming and me and Marshall just keep fighting them off. I feel exhilarated with each skeleton my sword dissembles. Marshall hasn't got a sword but he has fist and he can kick.

Just as we take out the last skeleton, I lose my footing and slip and fall. As I fall I grab hold of Marshall for support but I end up taking him down with me.

I end up lying flat on my back and probably have earned a nice collection of bruises too. After I stop seeing stars, I notice something that shocks me.

When I fell and dragged Marshall down with me, he landed right on top of me. Our bodies our smushed together. Where chest to chest and our faces our inches from each other. I'm so close I can smell him. I suddenly want to embrace him and just inhale that scent and stare into those eyes that are staring into mine.

Marshall doesn't seem to notice the awkwardness of the situation. Instead his eyes are full of concern.

"Fionna, are you OK?" he asks, his tone urgent.

"I'm-I'm fine, M-Marshall"

We climb to our feet hurriedly.

Me and Marshall make it our way to end of the hall until we come to the stairs that lie at the end of the hall. The stairs, like the rest of the room are full in cobwebs so I have to jungles style slice them away to clear the path. After a while it leads into another door, but this one isn't locked but instead swings open. Inside there's another room.

The room has deep purple walls along with a large four poster bed that is covered in red and black silks and an abundant of pillows. There's a small bathroom off to the side. I hold up my sword but the room seems to have no other pieces of furniture in it. There's only a bed.

"Hey, Marshall" I ask "What was this vampire dungeon used for?"

"Well, at lot of vampires used their dungeons as there lairs. I think this one had a mistress."

"A mistress?"

"It's a sort of pet name vampires give to their girlfriend or wife's, it's kind of an old-fashioned term"

"I guess this must have been there room" I say and can't help but smile when I see Fionna blush as she realises what this room was probably used for.

_Marshall's POV_

I watch as Fionna walks around the room and I think of how I fell on top of her a few minutes ago. I remember the feel of her human body against him. How warm she was. How much I really wanted to feel that warmth again. And not just any warmth but _her_ warmth. I remember how I felt her tremble underneath me and how I wanted to do things to her that would cause her to relax and her trembling to cease.

I watch as she pulls back one of the silk curtains that hide the bed and as she kneels down on it.

"Hey Marshall, look at this" I hear her say.

I move around the other side of the and kneel down on it, like she does.

Above the bed is a heart carved into the wall. Inside the heart there's the words _two lovers lie underground, never to be found, With each other they spend their nights, They don't need any lights, The two vampires with their love are bound together for the rest of the night and their immortals lives_

"Yeah, vampires kind of have this whole love of dark romance" I say

"They must have really loved each other" she says, her voice transfixed. Then in a smaller voice I hear her whisper "I wish someone loved me like that" I don't thinks he meant for me to hear that but I reply to it anyway

"Fionna, have you ever even kissed a boy?" I ask

Fionna's silent for while like she's ashamed of it but then slowly shakes her head.

"Fionna" I say. She turns to me and our eyes lock. The atmosphere around us is thick and heavy. I look at her face and I realise something for the first time. Fionna isn't just pretty, she isn't just attractive. She's also beautiful.

"Fionna, put your sword away"

_Fionna's POV_

I do as he says. I collapse my sword and with fumbling hands slide it back into my purse. I'm now utterly in the dark without its light. Marshall can see me but I can't see him. But somehow I feel him near me. I feel cold a pair of hands be gently placed on my shoulders. I feel his breath against my face and neck. My heart's beating so loud it's a wonder he doesn't hear it and my breath gets caught in my throat. I sit still and I wait.

Then suddenly he's kissing me.


End file.
